Building a Barracuda

Barracuda Fairing Phase 3

12/5/99 - I have begun work on the fairing for the Y2K races. The hardest part was figuring out where in my already crowded garage to store the plug, which would be almost 10ft long with the addition of the new tail. I finally ended up building a storage rack above the car to hold the plug (and my 12ft long  HPB hulls), which enabled me to start working on the fairing again. 

I created a template, and cut out the stack of foam aero shapes that would become the Barracuda tail. I then epoxied it to the existing foam stub on the back of the fairing plug. After many hours of shaping with the course file, I now have the shape roughed in. Here's the Barracuda fairing plug doing it's rendition of "whale on the beach" Note the piles of pink foam... barracuda-fair-v3-1.jpg (6663 bytes)
barracuda-fair-v3-2.jpg (5317 bytes) 12/11/99 - Here's a photo of me sitting on the 'Cuda low racer in front of the fairing plug, that I will use to create the canopy. A 10 foot long streamliner doesn't look so big when you see what has to fit inside!
1/15/00 - I made a template for the canopy out of plywood, then made a trip to the WISIL skunkworks (Bill Murphy's basement) to blow the canopy. We used 80 mil PETG plastic (scraps from the WISIL blown nosecone project) , and managed to get a decent bubble after the second try.  Below is a picture of the canopy resting on the 'Cuda 2.0 fairing.

I also gave some though to a sticky problem with full fairing design, ventilation. Too little and you get heat stroke in the middle of a race and bonk, too much and it takes away from your hard fought streamlining, and you go slower. 

barracuda-fair-v3-5.jpg (5808 bytes)
barracuda-fair-v3-6.jpg (4418 bytes) The vent I put in the 1.0 Barracuda fairing seemed to work pretty well, as it blew air right in my face, where it would do the most good. That design was a "snorkel" scoop, which was not too aero. I have seen some information on NACA ducts that looks like it may be a good compromise between ventilation and aerodynamics, so that's what I'll try this time. It will be a medium sized duct directly in front of the canopy. There should be a high pressure zone there to help the air into the duct as well. Something like:

5/14/00 - I took some time off the fairing construction to build the Barracuda Street Bike, then dove back in. I covered the raw foam tail section with a layer of fiberglass/epoxy, then began the tedious process of filling in the rough fiberglass surface and other irregularities with stinky Bondo. A few weeks ago I decided I was finally "finished", or close enough... After the surface was smoothed, I sprayed a coat of flat black paint on it, then sanded it again to fill in sanding scratches and find more imperfections. After filling those in with spot filler, sanding, spraying and sanding again, I was ready to wax the fairing plug. I put about 5 coats of wax on it, using almost a whole can of carnuba paste wax in the process. This filled in the remaining scratches and pits. I then coated one side of the mold plug with mold release agent. 

Finally... Ready to lay up a half shell! Bill Murphy graciously agreed to help me do the lay-up, and we spent a couple hours painting and squeegee-ing the West Systems epoxy into the two layers of 8oz crow foot weave fiberglass cloth. The hardest part was getting the bubbles out. Below is the fairing plug after the lay-up was completed. barracuda-fair-v3-3.jpg (9123 bytes)
barracuda-fair-v3-4.jpg (2782 bytes) I let the epoxy cure overnight, then slid a long chunk of Coroplast between the plug and the mold to remove the fairing half shell from the plug. It peeled off fairly easily. Here's what the fairing looks like, with the plug still inside (The blue strap is used for carrying it):
6/17/00 -
Over the course of the past month, I have trimmed and joined the two halves of the fairing. To do this, I put both halves of the fairing back on the male plug, applied the epoxied fiberglass to the bottom half of the fairing, waited until it had cured, and then slid the plug out. Joining the top half was more difficult and time consuming, I had to make small tabs to hold the fairing halves together properly while the epoxy cured.   After the fairing was made whole, I cut the canopy section off, and glassed the inside of most of the seam to strengthen the joint. At this point, I could actually put the bike inside the fairing!
barracuda-fair-v3-7.jpg (4089 bytes)
barracuda-fair-v3-8.jpg (5379 bytes) With the bike in the fairing, I marked and cut the wheel holes in the bottom of the fairing. I'll also need make a small fiberglass "trough" in the bottom to allow the chain to have a little extra clearance. In the previous fairing, it just hung in the breeze, causing drag. I probably lost a whole mile per hour right there...  I made the front fairing mounting bracket from a 7/8" aluminum tube, suspended horizontally across the forward upper  part of the fairing, and attached with pop rivets to temporarily locate it. I also added a "rib" to the canopy to strengthen it. It was made from 1/8" x 1" self stick foam, with a layer a fiberglass over it. This next picture shows the head bubble with the canopy, as well as the rib.

The bubble is just just resting on top of the fairing now. I'm waiting until I can actually sit in the fairing to mount it so I can get the correct fore-aft alignment.

I discovered while racing at the Waterford, MI "Sportsman's Park" HPRA races, what I need even more than the new fairing to allow me to go faster in less than perfect track conditions. Front suspension! At cornering speeds over 25 MPH my front wheel would skip over bumps causing the front wheel to drift sideways. That, combined with lift from the wind made for some real white knuckle experiences. I guess I need to start working on the in-head tube suspension. Rob Wood, who has full suspension and won the event in the "Unlimited" class, was going 28MPH around corners that I needed to slow to 22MPH for.

I installed the chain trough, which fairs the chain and other hanging bits, finished the front, center, and rear mounting points, and added the foam/carbon fiber composite reinforcement to the floor section to allow me to step into the fairing with stepping through i
t. The picture below shows the inside of the fairing from the rear, as well as the mounting brackets.

With less than a week to go to the Northbrook races, I decided that I had better step things up! I had to cut a hole in the fairing for the landing gear to poke through, which was somewhat traumatic, but I got over it... 

barracuda-fair-v3-9.jpg (6842 bytes)

I used the template for the bubble canopy to cut a hole it the removable portion of the fairing, and attached it with pop rivets. There was no time for a fancy way to attach the removable portion of the canopy (the "top"), so I pop riveted in some Coroplast to overlap the joint, then fashioned some aluminum clips, and attached them to the "top" with 5 minute epoxy. A couple wire ties in front so it doesn't blow off, and... Good enough! Well, barely... I had to have someone tape the back of the "top" to the fairing at the races so it didn't rattle around and lift off at high speeds, but it worked out OK. 

barracuda-fair-v3-10.jpg (8130 bytes) I spent a day or so finishing the outside of the fairing. I covered the fairing with a thin layer of "aeropoxy lite", a lightweight epoxy based filler, similar to body putty, but less toxic, and easier to sand. It still took way too long to sand, but after sanding and a coat of flat white primer paint, it looked presentable. Last but not least I needed to be sure I didn't overheat in the fairing. I've been there and done that and it's no fun. It was time to build the NACA duct. Details on building the duct can be found here. This is what the fairing looked like the day before the Northbrook race:
Racing went very well. I wasn't able to do well in the sprints, as I wasn't familiar with the bike yet, but during the 100 lap race, once I got used to the corners, I was blazing around the track at 36 to 38MPH. Umm, until my chain fell off. Somehow I still ended up in 3rd place...

This speed was limited by the short track, as I wasn't really working hard. I think I should be able to cruise at around 40, maybe faster on a longer track. Again I realized that suspension is a necessity.

Picture by Eric Vann

I reinforced the nose section to prevent the nose from being deformed by the wind during transportation on the open trailer at 70MPH. I suppose a closed trailer would have prevented this too... I also fixed the lower mount to better center the bike in the fairing, and make it easier to install and remove the bike.

I got a chance to try this out at the Sparta races, as I had a flat tire during the race at the airport. I thought the "short" 2/3 mile oval NASCAR track in Tomah, Wis would give me a chance to "open it up", but due to the flat corners, I think I was actually slower than at the Northbrook velodrome. I hit a small rock while following Rob Wood around a corner, crashed, and slid off the track. Nothing seemed damaged, so I took off the top and got back in the race. I wasn't much slower, as the speed had been limited by the corners, but I had to work a lot harder! A track worker mentioned that Rob and I were turning faster times than a lot of the cars that race on that track. Go figure.

I finally painted the fairing!  

barracuda-fair-v3-11.jpg (5813 bytes)    barracuda-fair-v3-12.jpg (3465 bytes)

10/30/00 - 
Added a chunk of plastic to better fair the rear of the canopy.
Here I am, racing in Ohio...
5/02/01 - 
Over the past winter I have added a front suspension to the 'Cuda, using an Action-Tec in-head shock unit. I also reshaped the bottom of the streamliner to provide clearance for the added 1.5" of wheelbase, get rid of the chain trough, and clean up the underside of the fairing, and made a set of fiberglass wheel disks. The front suspension helped immensely in the corners, and seems to be
a necessity for a fast streamliner. The picture below is me racing at the Indy HPRA races in April
I finally figured out an easy (and cheap) way to attach the canopy which will allow the fairing open on a hinge, and be held in place by Velcro fasteners on the inside. This will eliminate my current need to have somebody tape my in before the race, and then un-tape me after. It gets pretty hot sitting in
the bike after a race on a hot day, waiting for someone to un-tape you and let you out...
The hinge in back is made from some 3" by 1/8" thick aluminum stock that I picked up at Home Depot. I made four "L" shaped pieces that are held together by a bolt in back, and are pop riveted (for now) into the fairing.

The props, which are made from 3/4" x 1/8" aluminum stock, hold the fairing top open by locking in the over-center position. I drilled a bunch of holes in the props to make them lighter, plus it looks cool!

The hinge sticks out the back a little, but that shouldn't effect the aerodynamics too much. Right now I'm using bolts through the outside of the fairing to hold the props, but later I'll epoxy some brackets to the inside of the fairing. The paint is getting a little ratty from the work I did on the underside of the fairing last winter, and from the touch ups needed after falling over. I don't think that will slow me down though, so I'm leaving that alone for now.

Next steps: Reinforce the canopy, create a new rear end for the bike to enable the addition of a 26" or 700c rear wheel with suspension. Fortunately, there is room in the fairing! I figure this will help the top end speed by reducing rolling resistance and allowing higher gearing. The suspension should help in the corners. Also since the rear end will be removable, I'll be able to switch back and forth between wheel sizes. The ability to remove the rear end will make the bike able to be packed for travel too.

10/30/01 - 
This bike is now dialed in. I won almost every race I entered this year including the HPRA North American Championships. Cool!

4/24/02 - 
Over the past winter, I hacked off the 406mm rear end of the 'Cuda lowracer, and added a 700C rear end and wheel, in hopes of increasing the speed of the bike. I decided to forego the suspension and interchangeable rear ends to try to save weight. 
I finally had some time to retrofit the Barracuda lowracer chassis into the streamliner body. The now longer (and heavier) bike still fits into the fairing (barely), but has exposed a slight twist in the tail of the body (doh!), which meant I had to cut a slot in one side of the tail so the tire didn't rub. I was able to fill the slot in the side of the body where the landing gear folded up, so hopefully that will compensate. I took a couple runs around the block to test to make sure everything still works... Aside from needing a paint job, it's ready for the first race at Indy!

I didn't win ALL the races this year, but I'd still like to. The 700C rear wheel doesn't really help the speed noticeably. It seems now I am mostly held back by the body scraping in the really tight corners. At this years World Championships in Canada, I was paced handily on all the courses with sharp corners (Yes, all the courses had sharp corners) by Thomas Schott on his Razz Fazz. 

I need to start work on a new streamliner.

I also had a wonderful opportunity to race the 'Cuda at the World Human Powered Speed Championships this past October. During the week long event I was to crank it up to 58.5MPH on the long flat road, while spinning wildly at 120RPM in top gear. The Cuda design constantly amazes me. I know I could have broken 60MPH if I had some bigger gears and now I'm curious just how fast I could have gone. 
Since my new speedbike is working well, I sold this one to Dennis Grelk


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